1. Field of the Invention
This invention relates to a railway fastening for use in combination with a railway bridge girder and a cross-tie, and in particular to an adjustable railway fastening in the form of a resilient clip for securely fastening a girder to a cross-tie on a bridge or other supporting structure which provides an ability to vary the location of the fastening bolt and thereby the effective length of the fastener.
2. Description of the Prior Art
Various railway fastenings are described and shown in the prior art but there is a need for a simple reliable railway fastening for securing a girder to a cross-tie on a bridge or other supporting structure.
U.S. Pat. No. 3,552,649 to Burwell shows a railway fastening for resiliently securing a cross-tie on a bridge in the form of an elongated resilient clip of rectangular cross-section. The clip has a flat end bearing portion for engaging the lower face of a tie and an arcuate bearing portion at its opposite end to bear against a bridge girder or cover plate for securing the tie to the girder. The arcuate portion of the clip has an elongated slot extending longitudinally on the clip to receive a bolt having a diameter substantially less than the length of the slot and such as to slidably engage the sides of the slot. This slidable engagement enables the angular position of the clip to be adjusted relative to the bolt to thereby adjust the position of the arcuate bearing portion so that the clip can be used with cover plates or girder flanges of substantially different thicknesses.
While this clip has performed satisfactorily in most situations, problems arise if the size of the steel tie plate that is on top of a wooden tie is increased, so that the steel tie plate is actually wider than the flange of the steel girder underneath the tie. The top tie plate then interferes with drilling a bolt hole to permit the tie to be fastened to the girder flange. It now becomes necessary to move the bolt hole to the side of the girder flange. Consequently, if the bolt is placed outside of the tie plate it will not be next to the girder after passing through the tie and the tie will not be securely fastened. In addition, when the bolt passes through the arcuate portion, care must be taken to avoid excessive tightening of the bolt which can limit the desired resiliency of the clip in securing the girder.
U.S. Pat. No. 3,659,784 shows a bracket for use with a clamp and screw spike adapted to clamp elevated railroad ties to a support structure. The bracket comprises a U-shaped member with a base portion and vertically extending wing portions. The base portion is provided with a washer held in an elongated slot. The washer registers with the nut shaped portion of the screw spike to enable the vertically extending wing portions of the bracket to be positioned for securing to the tie. The bracket prevents the screw spike and clamp from disengaging and falling from the tie.
Other rail fastening devices are shown in U.S. Pat. No. 3,796,369 in which one portion of the fastener overlies the rail flange and the other portion contacts a supporting surface and is secured thereto to resist rotational movement. U.S. Pat. No. 3,362,639 shows another rail fastening that is in the form of a spring clip having a compression arch, a rail flange engaging end, and an intermediate rib provided with a depending rail side edge engaging portion. Tightening of a pressure block disposed above the clip flexes the arch and rib to embrace the rail and inhibit both longitudinal and laterial displacement of the rail.
Another rail fastening in the form of a clip for positioning a rail to a sleeper is shown in U.S. Pat. No. 4,254,909. The clip shown there is a spring plate, shaped so that when retained near its midpoint, one end bears against the upper surface of the rail while the other bears against a sleeper or bearing pad on the sleeper. The slit is urged downwardly against the foot of the rail by a loop extending upwardly from the sleeper and a locking pin passing through the loop and bearing against the intermediate locality of the clip.
The invention of the aforementioned parent application contemplated a resilient clip having a substantially planar body portion with an opening for a bolt which is offset with respect to a bridge girder or cover plate, a girder flange engaging end in the form of a resilient compressions arch to restrain vertical movement, and a tie engaging end having downwardly and outwardly extending ears for laterally restraining the cross-tie. A shoulder on the resilient arch also engages the side of the girder flange to provide further lateral restraint. In effect, the clip resembles a relatively flat spring washer with an arched end which, when a bolt is inserted through the opening and a bolt-tensioning member, such as a nut, is secured to the bolt, presses against the girder flange, while the ears press against the cross-tie to restrain lateral and vertical movement thereof.